• Title, Summary, Keyword: chemical properties

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Chemical Modification of Poly(vinylacetylene) and Synthesis of Poly(1,2,3-triazole)s

  • Wang, Lian-Jun;Liao, Shan;Wang, Le-Yong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1471-1474
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    • 2011
  • A series of new polymers containing 1,2,3-triazoles were synthesized and their structures and properties were characterized by FT-IR, $^1H$ NMR, TGA, DSC and GPC. The results showed that the polymers modified by alkyl groups had good solubility, thermal stability and reasonable molecular weights. It was also demonstrated that the properties of fluorine-containing polymers were seriously affected by fluorine atoms with hydrophobic and chemical proof properties.

Study on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

  • Qian, Yi-Hua;Huang, Yi-Bin;Fu, Qiang;Zhong, Zhen-Sheng
    • Journal of Electrical Engineering and Technology
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    • v.8 no.3
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    • pp.588-594
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    • 2013
  • Under the condition of Baader aging, the chemical composition variation and the influence of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as interfacial tension were studied in the aging precess. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were also investigated. The results show that these parameters of physic-chemical and electrical properties of hydrogenated transformer oil relate to each other and have closed correlation with chemical composition.

Study on the Different Characteristic of Chemical and Electronic Properties (SiOC 박막의 화학적 특성과 전기적인 특성에 대한 차이점에 관한 연구)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.18 no.1
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    • pp.49-53
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    • 2009
  • The chemical properties of SiOC film was studied for inter-layer insulator. SiOC film was formed with non polarity due to the appropriate union by the alkyl and hydroxyl group. An amorphous structure of non polarity can induce the low dielectric constant materials. The chemical properties of thin film can define the bonding structure owing to the ionic variation, and the analysis of chemical properties was researched by the carbon content using the FTIR spectra, and induced the film with non polarity. The electrical properties is the electron flow, and is always not the same as the chemical properties. The electrical properties of SiOC film with various flow rate ratios was analyzed and researched the correlation between the chemical properties. SiOC film showed the increasing of the leakage current after annealing process, and abruptly increased the carbon content at some samples. But the sample with increasing the carbon content decreased the leakage current. It means that the chemical properties is not the same as the electrical properties, and the carbon is related with the variation of the bonding structure, and does not contribute the current flow.

Effects of solvents on rheological and crosslinking properties of photo-polymerized poly(ethylene glycol) hydrogels

  • Jung, Kevin Injoe;Lee, Dong Geun;Bong, Ki Wan;Noh, Seung Man;Um, Min Seop;Choi, Woo Jin;Kim, Bumsang;Jung, Hyun Wook
    • The Korean Journal of Chemical Engineering
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    • v.34 no.5
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    • pp.1517-1523
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    • 2017
  • The effects of solvents such as water and ethanol on the rheological properties and crosslinking characteristics of poly(ethylene glycol) (PEG) hydrogels were examined. Real-time storage modulus data for pre-polymerized mixtures containing different solvents during the photo-polymerization process successfully explained the differences in the formation of crosslinked networks of the corresponding hydrogels. Various experimental methods for Fourier transform infrared spectroscopy (FT-IR), swelling ratio, Rhodamine-B (Rh-B) loading/release properties, and scratch/indentation depths on hydrogel surfaces, were employed to systematically compare macroscopic structural and mechanical properties of the crosslinked PEG hydrogels with different solvents (water and ethanol). The effects of the solvents on the hydrogel properties were satisfactorily consistent, and the results clearly indicated that water hindered the formation of the crosslinked network more severely than ethanol at the same weight ratio because of the presence of larger number of water molecules in pre-polymerized mixtures, which was a more favorable feature for water than ethanol in the initial crosslinking growth.

Estimation for Retention Factor of Isoflavones in Physico-Chemical Properties

  • Lee, Seung-Ki;Row, Kyung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.24 no.9
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    • pp.1265-1268
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    • 2003
  • The estimation of retention factors by correlation equations with physico-chmical properties maybe helpful in chromatographic work. The physico-chemical properties were water solubility (S), hydrophobicity (P), total energy ($E_t$), connectivity index 1 ($^1{\chi}$), hydrophilic-lipophlic balance (x) and hydrophilic surface area (h) of isoflavones. The retention factors were experimentally measured by RP-HPLC. Especially, the empirical regulations of water solubility and hydrophobicity were expressed in a linear form. The equation between retention factors and various physico-chemical properties of isoflavones was suggested as $k = a_0 + a_1\;log S + a_2log\;P^Q + a_3(E_t) + a_4(^1{\chi}) + a_5(x) + a_6(h)$, and the correlation coefficients estimated were relatively higher than 0.95. The empirical equations might be successfully used for a prediction of the various chromatographic characteristics of substances, with a similar chemical structure.

Synthesis of a Novel Phosphorus-containing Flame Retardant for Epoxy Resins

  • Xu, Hong-Jun;Jin, Fan-Long;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2643-2646
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    • 2009
  • In this study, a novel phosphorus-containing flame retardant copolymer of spirocyclic pentaerythritol di(phosphate monochloride) and bisphenol S (SPD-BS) was successfully synthesized and used as a flame retardant in diglycidyl ether of bisphenol A (DGEBA) epoxy resins. The chemical structure of the SPD-BS was characterized using FT-IR and $^1H$ NMR spectra. The thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The effects of SPD-BS and nano-$CaCO_3$ on the flame-retardant properties of DGEBA/SPD-BS systems were evaluated by measurement of the burning rate. As a result, the thermal stabilities of the DGEBA/SPD-BS systems were decreased with increasing SPD-BS content. The flame-retardant properties and char yields of the systems were significantly increased when SPD-BS content increased. The synergism of nano-$CaCO_3$ incorporation on flame retardancy was found for the DGEBA/SPD-BS systems.

Gas Separation Properties of 6FDA-Based Polyimide Membranes with a Polar Group

  • Park, Sang-Hee;Kim, Kwang-Je;So, Won-Wook;Moon, Sang-Jin;Lee, Soo-Bok
    • Macromolecular research
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    • v.11 no.3
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    • pp.157-162
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    • 2003
  • 6FDA-based polyimides were prepared from the thermal imidization reaction of 6FDA with diamines of BAPAF, DAP, and DABA having a polar group of hydroxyL or carboxyl. Properties of the dense polyimide membranes were characterized and their gas permeation properties for H$_2$, $CO_2$, $O_2$, $N_2$, and CH$_4$ were investigated. Permeabilities, diffusion coefficients and diffusivity selectivities of polar group-containing polyimide membranes including 6FDA-BAPAF, 6FDA-DAP, and 6FDA-DABA polymer for the gases did not change largely. The separation properties of 6FDA-TrMPD polyimide membrane used as a reference polymer were compared with those of the polyimide membranes mentioned above. It was found that the polyimides of 6FDA-BAPAF, 6FDA-DAP, and 6FDA-DABA, which were soluble in alcohol or/and 2-methoxyethanol, could be applicable to the preparation of a dense composite membrane by dip-coating method.

Prediction of Chemical and Physical Properties by Climatic Factors in Flue-cured Tobacco (기상요인에 의한 황색종 잎담배의 이화학적 특성 예측)

  • Jeong, Kee-Taeg;Cho, Soo-Heon;Bock, Jin-Young;Lee, Joung-Ryoul
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.1
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    • pp.1-7
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    • 2007
  • This study was conducted in order to predict the chemical and physical properties by climatic factors during the growing season of flue-cured tobacco as soon as possible. The data of eight chemical and five physical properties were collected from "Analysis of physical and chemical properties on farm leaf tobacco" conducted at KT&G Central Research Institute from 1987 through 2006. Data of climatic factors from April to July in 10 districts were collected from Korea Meteorological Adminstration. Except for yellowness(b), all probabilities of linear regression equations between the climatic factors(X) and the average contents of twelve grades(whole plant) for chemical and physical properties(Y) were significant($P{\leq}0.05$). The predicable probabilities within ${\pm}20%$ range of difference were 100% in ether extract content, in nicotine content, and in filling value, 90% in total nitrogen content, and 70% in total sugar content. These results suggest that the regression equations may be useful to predict the average content of twelve grades for eight chemical and four physical properties by climatic factors during the growing season of flue-cured tobacco at the beginning of August.

Prediction of Chemical and Physical Properties by Climatic Factors in Burley Tobacco (기상요인에 의한 버어리종 잎담배의 이화학적 특성 예측)

  • Jeong, Kee-Taeg;Cho, Soo-Heon;Bock, Jin-Young;Lee, Joung-Ryoul
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.1
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    • pp.8-13
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    • 2007
  • This study was conducted in order to predict the chemical and physical properties by climatic factors during the growing season of burley tobacco as soon as possible. The data of six chemical and five physical properties were collected from "Analysis of chemical and physical properties on farm leaf tobacco" conducted at KT&G Central Research Institute from 1987 to 2006. Data of climatic factors from April to July in 6 districts were collected from Korea Meteorological Adminstration. Except for total nitrogen, total nitrogen/nicotine and yellowness(b), all probabilities of linear regression equations between the climatic factors(X) and the average contents of twelve grades(whole plant) for chemical and physical properties(Y) were significant($P{\leq}0.05$). The predicable probabilities within ${\pm}20%$ range of difference were 100% in ether extract content, 95% in nicotine content, and 90% in filling value. These results suggest that the regression equations may be useful to predict the average content of twelve grades for four chemical and four physical properties by climatic factors during the growing season of burley tobacco at the beginning of August.